Safety device for internal-combustion engines.



H. LEMP. SAFETY DEVICE FOR INTERNAL COMBUSTION ENGINES. APPLICATION nun DEC. so. 1912.

1,080,765 Paten ted Dec. 9, 1913.

Witness e s:

invent on Her-mannLe'mp, Mam w His J1 t orne gi HERMANN LEMP,

OF ERIE, PENNSYLVANIA, ASSIGNOBL TO GENEPaAL-ELECTRIC COMPANY, A CORPGRATION OE NEW YORK.

SAFETY DEVICE FOR INTERNAL-COMBUSTION ENGINES.

Specification of Letters Patent.

- late'nted Dec.9, 1913.

Application filed December 30, 1912. Serial No. 739,205.

To' all whom, it may concern:

Be it known that I, HERMANN LEMP, a citizen of the United States, residing at Erie, in the county of Erie, State of Pennsylvania, have invented certain new and useful Improvements in Safety Devices for Internal-Combustion Engines, of which the following is a specification.

From time to time serious accidents occur in power plants having. high compression engines operating on the constant pressure plan. The accidents, often resulting in the loss of life or limbs-are caused by the bursting of the air tanks or blast bottles as they are commonly ealled. These bottles, which supply the necessary air to inject the fuel, are under very high pressure, 900 to 1000 pounds per square-inch not being uncommon. Various theories as to the cause of these accidents have been advanced but no complete remedy has heretofore been devised to my knowledge. Careful analysis shows that the real cause is due to the more or less gradual accumulation of vapors of fuel or libricating oil in the air blast bottles and in the pipes leading therefrom to the engine pulverizers until a highly combustible mixture is formed which is ignited by a rise in temperature due to ,a flame or hot charge blowing back from the engine cylinder through the fuel admitting'valve of the pulverizer. To give an approximate idea of the situation under the conditions specified, the pressure in one of these hottles would probably be from two and onehalf to three times the normal air pressure, and the bottle would burst unless the factor of safety was very much higher than is These accidents are.

normally necessary. comparatively rare, a fact which renders necessary some form of safety device which does not become inoperative from lack of attention or use. J

, The object of my invention is to provide a safety device which will fulfil the conditions referred to abov In the accompanying drawing, which illustrates one of the embodiments of my invention, Figure 1 is a partial view of an internal combustion engine equipped with my improved safety device; Fig. 2 is a view inside elevation of the safety device; and Fig. is a sectional view thereof.

4 indicates the cylinder of an internal combustion engine operating on the constant the pipe. 8 leading pressure plan. That is to say, an enginein which air is compressed to a temperature above the igniting temperature of the fuel, which fuel is injected through'a pulverizer or atomizer into the combustion space by a blast of air under high pressur 5 indicates a fuel p'ulverizer of any suitable or well known construction. Fuelis admitted thereto by the pipe 6 and high pressure compressed air from the blast bots tle 7 by'the pipe 8. The admission of fuel to the engine is controlled by the needle valve 9 which is actuated by the lever 10 from the cam shaft. from the blast bottle 'is controlled by the hand valve 11, In the pipe 8 between the blast bottle and fuel pulveriz'er is situated my improved safety device 12. This device should be mounted close to the engine and preferably on the pulverizer itself: The

safety device comprises a casing 13 havinga' screw threaded nipple for mounting it on The passageef air i the pulverizer, and a second screw threaded nipple to receive the couplin of pipe 8. In the casing is a passage 14w ich may extend diagonally with respect to the axis of the needle valve so thatin the event of back firing in the engine as little resistance as,

possible will be ofl'ered to the passage of the gases, as in Fig. 1, or it may extend perpendicular to the axis of the pulveriz er as in Fig. 2.

The passage 14: terminates in a chamber 15, one wall of which is formed by a thin metallic diaphragm 16. The diaphragmis held in placeby a nut-17 that is screw threaded to the casing. The nut is provided with a central opening-l8 of relatively large area. The diaphragm can-with advanta 2e be made of thin copper and in ordinaryservice should be capable of withstanding a pressure of from 2000 to 2500 pounds per square inch. This pressure will be determined by the blast pressure and by thepressure in the combustion chamber of the engine.

Located at one side of the passage 14 is second passage 19 that communicates with p th starting bottle. The mouth of this p shaped to form a conical seat for the cal valve 20. This valve is free to open when air [lows from the bottle to the engine, but closes and preven s the passage of .luid fii-om the engine to the bottle. The valve and its seat are so orranged with respect to the diaphragm that the latter acts as a means to prevent the valve from getting out of place.

It will be noted that the passages 14 and 19 are parallel for a portion of their length. This serves as an additional means to prevent the passage of gases from the engineto the bottle for the reason that when back" firing occurs the gases strike the diaphragm 16'and disrupt it, there being comparatively little tendency of the gases to turn and flow through the passage 19 in the opposite direction. In any event the ball valve would close and prevent this action from taking fail to operate under abnormal pressure co'nditions and does not require to be tested from time to time to see if it is in good co'ndition. Any. deterioration of the material would 'merely mean that the diaphragm would blow out at a little lower pressure than was originally intended; This would not be harmful. i I By making the diaphragm out of copper, or somesimilar material, it will be torn or split when disrupted, as distinguished from bodily separating the central part of the diaphragm from that under'the retaining nut. .Due to this fact the operator is not line with the diaphragm at the time.

endangered even though he is standing in In practice the safety device should be so positioned that the diaphragm is pointed away from any place that the operator is required to stand in the performance of his duties. Preferably the diaphragm is pointed upwardly.

a fuel In accordancewith the provisions of the patent statutes, I have described the principle of operation of my invention, together with theapparatus which I now consider to represent the best embodiment thereof; but I desire to have it understood .that the apparatus shown is only illustrative and that the invention can be carried out by 7 other means.

What I claim as new-and desire to secure 'by Letters Patent of the United States, is,-'-

1. An internal combustion engine having ulverizer, and a blast bottle con nected t ereto for introducing fuel into the engine cylinder in combination with a safety device interposed between the pulverizer and bottle which comprises a casing, a thin metallic diaphragm which is normally exposed to the pressurein the blast bottle and under abnormal conditions to the pressure in the cylinder, and a check valve which is opened by the fluid flowing from the bottle tothe engine and is closed by fiuid tending to flow in the opposite direction.

2. An internal combustion en ine having a fuel pulverizer and a blast ottle connected thereto, in combination with a safety device comprising a casin" containing a chamber, a passage leading t erefrom to the pulverizer, a thinmetallic diaphragm forming one wall of the chamber, a second passage communicatin with the chamber and the blast bottle, sai pass es being offset to prevent direct flow o fiui from one 'to the other, and a check valve whichisflocate d .in the second passage bet-ween thelchu'nber'and the bottle. t a In witness whereof, I havenhere mtonset my hand this 26th day of December, '1912.

HERMANN LEMP.

Witnesses: Z i I ALFRED G. Monarongp Orro F. PERsso Copies of this patent may be obtained for five cents each, by addresslng' the Commie sinner of intent, Wash1ngton,-'D. 0. 

